WO2016138994A1 - Blank for producing dental replacement parts, said blank having a dentine zone which is embedded in an enamel zone - Google Patents

Abstract

The present invention relates to a blank (1) for producing dental replacement parts, which blank (1) has a dentine zone (7) which is embedded in an enamel zone (8). The object of the invention is to make available blanks for producing dental replacement parts which can be produced with a reduced number of shapes and deliver a predictable visual result. According to the invention, this object is achieved by a blank (1) which is used for producing dental replacement parts and which has a dentine zone (7) embedded in an enamel zone (8). The blank (1) according to the invention is characterized in that a first part (2) of its outer surface has the shape of a surface portion of a first tooth, and at least a second part (3) of the outer surface of the blank has the shape of a surface portion of a second tooth.

Description

 ROHLING FOR THE MANUFACTURE OF TOOTH PARTS THAT HAS A DENTINE ZONE EMBEDDED INTO A MELTING ZONE

The present invention relates to a blank for the manufacture of dental prostheses having a dentinal zone embedded in a molten zone.

From WO 01/58378 A1, an assortment of functionally and color-tailored prefabricated teeth is known, whose outer dimensions in the marginal region should be larger than a prepared tooth. The prosthetically produced prosthetically produced dentures can be produced with a high surface quality and must only be slightly processed to adapt to the individual situation in all visible or functional areas. The high factory achievable surface quality is not diminished by extensive processing. In addition, the optical surface appearance does not change by machining, so that e.g. a once chosen coloring is also preserved. The teeth of the set of teeth may also be e.g. color-produced, creating a natural impression. By editing the visible surface of this impression would be deteriorated. The tooth replacement parts according to WO 01/58378 A1 are only marginally larger than a prepared tooth stump, so that the adaptation to the prepared tooth stump in this area can be achieved by material-removing methods, such as e.g. Grinding or milling, can be done. The tooth surface is little mechanically stressed in this area and hardly visible in everyday life, so that it depends on a high surface quality less.

Disadvantage of the tooth assortment according to WO 01/58378 A1, however, is that many different shapes are needed to produce a complete set of teeth in all sizes.

CONFIRMATION COPY From DE 10 201 1 1 16 853 A1 a tooth replacement mold block for the production of a tooth replacement part is known, in which a dentinal zone is embedded to form an interface in a melting region. The dentinal zone is supposed to form two apparently different dentin surfaces with a slightly convex curvature. As a result, the tooth replacement mold block can be ground so that a tooth replacement part with a labial surface is formed, to which the first or second dentin surface is directed. By appropriate alignment of the dental prosthesis mold block different dental prostheses can thus be worked out of a block, in which the orientation of the dentin core can be influenced on the labial surface of the dental prosthesis. Different optical results, depending on the orientation and distance of the dentin surface to the surface of the dental prosthesis, are the result.

Disadvantage of this solution, however, is that the surface of the denture mold block must be completely ground, which affects the surface quality. In addition, the influence of the position of the dentin surface relative to the surface of the finished dental prosthesis part on the color effect can be finally assessed only after completion of the dental prosthesis part. The aesthetic result can not be accurately foreseen.

It is therefore an object of the invention to provide blanks for the manufacture of dental prostheses which can be manufactured with a reduced number of shapes and provide a predictable optical result. According to the invention we have achieved this object by a blank for the production of dental prostheses, which has a Dentin zone, which is embedded in a molten zone. The blank according to the invention is characterized in that a first part of its outer surface has the shape of a surface section of a first tooth and at least a second part of the outer surface of the blank has the shape of a surface section of a second tooth.

For the aesthetics of dentures, it is important that the visible surfaces are of high quality. For the planning of a restoration, it is also necessary to achieve a result by suitable choice of the blank used to fits the adjacent teeth in the mouth of a patient. In terms of the factory, high-quality surfaces can be created that are very close to natural teeth. If the surfaces have to be processed, the surface finish may be deteriorated.

For this reason, the blank according to the invention has at least two different regions on its outer surface which correspond to two different surface cutouts of teeth, so that these regions no longer have to be machined or at least only slightly corrected for producing a tooth replacement part. Preferably, these surface cutouts are the labial and / or occlusal surfaces of the teeth.

From the blank thus a tooth replacement part can be worked out that uses one of the already corresponding to a tooth surfaces of the blank. Since this surface does not have to be or does not have to be processed essentially, the high surface quality in this area is maintained. Similarly, the visual impression, such as color, translucency, etc., remains unchanged, so that the processing result is predictable. If the part of the outer surface of the blank, which already corresponds to a part of the shape of a tooth, corresponds to a labial surface of a tooth, then the visual impression which the tooth replacement part leaves later in the dentition of the patient can be reliably predicted. If the surface is an occlusal surface, then there is a surface that can be subjected to a high mechanical load. If it is the labial and the occlusal surface, then all surfaces of a dental prosthesis, which should be mechanically stable and / or aesthetic, includes.

The processing of the remaining areas of the blank for the production of the dental prosthesis is irrelevant in terms of the surface quality, as any deviations in the aesthetic impression are not visible and not noticeable in practice.

To reduce the number of molds required, it is of decisive advantage that the blank according to the invention for the production of at least two different tooth replacement parts can be used. Including that part of its outer surface, which has the shape of a surface section of a first tooth, a first tooth replacement part can be worked out of the blank. Including that part of its outer surface, which has the shape of a surface section of a second tooth, a second tooth replacement part can be worked out of the blank.

With a blank mold blanks can thus be produced, from which at least two different tooth replacement parts can be produced, and in which at least one surface is retained in their fabrikatorisch produced quality and color design.

In practice it has been found that more than two different tooth replacement parts can be produced from a blank according to the invention with two surfaces corresponding to a surface section of a tooth. Dental replacement parts are required in different color designs and sizes. From a blank dental prosthesis parts of different sizes can be produced, since the processing on the edges has negligible influence on the aesthetics of the final result. Thus, e.g. a tooth replacement part with the size of exactly this surface can be produced from a blank with a surface corresponding to a section of a tooth, as well as a next smaller and a next larger tooth replacement part. In the former case, an area is milled out of the blank following the factory-made area, which naturally continues the area. The transition is negligible, as long as the worked-out additional surface remains relatively small compared to the fabrikatorisch produced area. Likewise, the fabrikatorisch produced surface can be ground at the edge to produce a tooth replacement part of lesser size.

In particular, the blank according to the invention can have a first and a second part of its outer surface, which have the shape of a surface section of a tooth, wherein these surfaces can face each other in particular. From such a blank, a first tooth replacement part can be produced by using the first part of the outer surface, the opposite second part corresponding to the outer surface is ground and thus lost. Conversely, another tooth replacement part can also be produced using the second part. For example, the first and second parts of the surface can be mirror-symmetrical, so that alternative tooth replacement parts can be produced for a tooth on the right or a tooth on the left side of the jaw.

The blank may also be designed so that it can be split and, for example, two dental prosthesis parts can be produced therefrom, one of which has a surface according to the first part of the outer surface of the blank and one surface according to the second part of the outer surface of the blank.

The blank according to the invention can also have three, four, five or more parts of its outer surface, which have the shape of a surface section of a tooth. Up to five such surfaces may preferably be arranged on the surfaces of an imaginary cube. The holder for machining the block of teeth can then be arranged on the sixth side of the cube. From such a blank, alternatively, at least five different dental prostheses could be produced, taking into account different sizes even at least 15.

The blank according to the invention is equipped with a dentin core, which consists of a natural dentin imitating material. The dentin core can be produced, for example, from a glass ceramic or an oxide ceramic, such as zirconium oxide. The dentin core is then veneered with an enamel-imitating material. This creates an interface between the dentin core and the enamel.

Preferably, the blank according to the invention is designed so that the surface of the Dentin zone is correlated within the blank in the region of the first and second parts of the outer surface of the blank with the surface of the blank, in particular substantially parallel thereto. As a result, a particularly lifelike effect of the blank in the region of its surfaces can be achieved, which correspond to a section of a tooth. The thickness of the melting zone above the dentinal zone in the region of the first and second parts of the outer surface of the blank may preferably be between 0.05 and 0.8 mm, in particular between 0.1 and 0.6 mm or between 0.4 and 0.6 mm.

The blank may preferably be provided with a reference geometry, e.g. a surface or edge, be equipped for the positioning of the blank in a processing machine. Tolerances in the production of the blank or in the bonding of the blank with a holder for attachment in a processing machine can then be detected and compensated by measuring the position of the reference geometry.

The blank according to the invention can be used in particular for the production of crowns, partial crowns, inlays, onlays and veneers.

Preferred embodiments of the invention will be explained in more detail with reference to the accompanying drawings.

Figure 1 shows a blank according to the invention in a lateral view of his

 Viewed from the front;

Figure 2 shows a blank according to the invention in a perspective view;

Figure 3 shows a glued with a machine holder invention

 Blank in lateral view with view of the labial surface;

FIG. 4 shows a blank according to the invention in section.

The blank 1 shown in Figure 1 is used to produce a crown of an anterior tooth. A first part 2 of its outer surface has the shape of a surface section of a first tooth, namely the labial surface of a right incisor. A second part 3 of the outer surface of the blank has the shape of a surface section of a second tooth, namely the labial surface of a left incisor. The two surface sections 2 and 3 are thus mirrored. The blank 1 can be used to make a crown for a left or a right incisor. Between the surface cutouts 2 and 3 is a frame-shaped material section 4, which provides sufficient material thickness in order to grind a crown out of the blank using one of the two surface cut-outs 2 or 3.

The surface sections 2 or 3 remain essentially unprocessed and retain their high, factory-produced surface quality. The color, translucency and flatness of the surface are retained. There can be no deviations from the processing that could worsen the result or jeopardize the use of the finished crown. The subsequent aesthetic effect of the crown can be determined in advance before editing by appropriate selection of the blank. The effect is not changed by the processing, since the decisive for the aesthetic effect surfaces remain essentially unprocessed.

If the material section 4 is chosen to be large enough, two crowns can also be produced from the blank using both surface cutouts 2 and 3.

The material section 4 is frame-shaped in the illustrated embodiment and thus represents a reference geometry, which can serve for alignment of the blank 1 in the bonding with a holder for receiving in a processing machine. In the production of the blank, it may, for. B. come by shrinkage of the material to light tolerances. The frame 4 provides clearly defined areas by which such inaccuracies can be detected and compensated. The bonding of the blank 1 to the machine holder 6 can be done much more accurately with the frame 4 as clearly defined reference geometry, in particular as regards the axial orientation.

On the basis of the frame-shaped material section 4 can also after the bonding of the blank 1 with a machine holder 6 and the clamping of the blank in a processing machine determines the exact actual position of the blank and the leadership of the processing tools accordingly be adjusted. Manufacturing tolerances and tolerances in the bonding of blank and machine holder can be compensated.

Figure 2 shows the same blank 1 in a perspective view. Good to see is the surface portion 2, which corresponds to the labial surface of a natural tooth. Furthermore, the frame-shaped reference geometry 4 can be clearly seen, which allows an exact measurement of the position of the blank with the flat surfaces 4a and 4b or the rounded edge 4c if the blank is to be glued to a machine holder or if the blank is clamped in a processing machine ,

To produce a crown, a partial crown, an inlay, an onlay or a veneer, the desired shape is milled out of the blank, wherein the surface portion 2 remains essentially unprocessed. To adapt to the required crown, at most the lateral edges of the surface are ground to adjust the size of the crown. This makes it possible to make crowns of different sizes from the blank, without having to produce a separate shape for each size. In order to adapt the size of the dental prosthesis part to be produced, the blank, following the surface 2, has a section 10 which has sufficient material to work out any desired shape following the surface 2 by ablation methods. The width adjustment can thus be done without difficulty.

To make a crown, the blank is ground in the marginal area 5 according to the situation in the patient's mouth and a lumen is created for connection to the tooth stump. The blank has on the side facing away in Figure 2 on another surface portion 3, which corresponds to the labial surface of another natural tooth so that the blank can be used for the production of two different crowns. Figure 3 shows a blank 1 according to the invention, which is glued to a holder 6 for fixing the blank in a processing machine. The blank 1 has a first surface portion 2, which corresponds to the labial surface of an incisor. The rear side of the blank, not shown in the figure, has a further surface section, which corresponds to the surface section 2 mirror-inverted. This surface portion can therefore be used to produce the corresponding incisor of the other side of the jaw. The position of the blank 1 clamped on the holder 6 in a processing machine can be determined by measuring the edge 4c serving as a reference geometry, so that tolerances in the production or in the bond between holder 6 and blank 1 can be taken into account and compensated for in the control of the processing tools ,

The marginal area 5 of the blank has enough material to be able to grind it to the crown can. Likewise, the transition region 10 to the holder 6 sufficient material to work out after the surface 2 any desired shape of the blank and, if necessary, to be able to adjust the width of the resulting dental prosthesis.

FIG. 4 shows a blank 1 according to the invention in section. The blank 1 has a Dentin zone 7, which consists of tooth-like material, such as. As glass-ceramics or oxide ceramics, and the dentin of a natural tooth to emulate. The dentinal zone 7 is embedded in a fusion zone 8 intended to mimic the enamel of a natural tooth. Again, the first part 2 of the outer surface of the blank and the second part 3 of the outer surface of the blank can be seen, whose shape corresponds to a surface section of a first and a second tooth.

The surface 9 of the dentinal zone is correlated in the region of the first and second parts 2, 3 of the outer surface of the blank 1 with the surface of the blank, in the illustrated embodiment such that the surface 9 of the dentinal zone 7 is substantially parallel to the outer surface of the blank in the region of first and second parts 2, 3 and their thickness is between 0.1 and 0.6 mm. The blank thus has its final aesthetics in the area of the surfaces 2, 3 which are no longer machinable in the production of a tooth replacement part. The essentially parallel course of the surface 9 of the dentinal zone 7 ensures a uniformly translucent impression. It can not happen that the layer thickness of the melting zone 8 and thus the aesthetic impression are changed by machining.

Claims

A blank (1) for producing dental prostheses, comprising a dentinal zone (7) embedded in a molten zone (8)  characterized in that a first part (2) of the outer surface of the blank (1) has the shape of a surface section of a first tooth and at least a second part (3) of the outer surface of the blank (1) has the shape of a surface section of a second tooth. Blank (1) according to claim 1, characterized in that the  Surface cutouts correspond to the labial surfaces and / or the occlusal surfaces of teeth. Blank (1) according to claim 1 or 2, characterized in that the blank has a first and a second part (2, 3) of its outer surface, which have the shape of a surface section of a tooth, and these surfaces face each other in particular. Blank (1) according to claim 3, characterized in that the first and the second part (2, 3) of the outer surface of the blank are arranged mirror-symmetrically. Blank (1) according to claim 1 or 2, characterized in that the blank has three, four or five parts of its outer surface, which have the shape of a surface section of a tooth, and these surfaces are arranged in particular on the surfaces of an imaginary cube. Blank (1) according to one of claims 1 to 5, characterized in that the surface (9) of the dentinal zone (7) within the blank (1) in the region of the first and second parts (2, 3) of the outer surface of the blank with the Surface of the blank is correlated, in particular substantially parallel thereto. 7. blank (1) according to one of claims 1 to 6, characterized in that the thickness of the melt zone (8) over the Dentin zone (7) in the region of the first and second parts (2, 3) of the outer surface of the blank between 0, 05 and 0.8 mm, in particular between 0.1 and 0.6 mm. 8. blank (1) according to one of claims 1 to 7, characterized in that the blank has a reference geometry for the positioning of the blank in a processing machine and / or on a holder of a  Processing machine has. 9. blank (1) according to one of claims 1 to 8, characterized in that the blank is made of a glass ceramic or an oxide ceramic.